A bimetallic doped hierarchical porous carbon catalyst, a preparation method and application thereof

Abstract

The application discloses a bimetallic doped hierarchical porous carbon catalyst and a preparation method and application thereof. The bimetallic doped hierarchical porous carbon catalyst is prepared from two transition metal salts and specific biomass powder as raw materials through 160-180 DEG C hydrothermal carbonization and 200-500 DEG C calcination. The catalyst has simple components, is cheap, and has a simple preparation process. The catalyst can efficiently catalyze synthesis of 2,5-furan dicarboxylic acid from 5-hydroxymethylfurfural under mild conditions. The target product has high yield and simple separation, and has a good industrial application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical engineering, and particularly relates to a bimetallic doped multi-level porous carbon catalyst and a preparation method and application thereof. BACKGROUND

[0002] Bio-based chemicals can be used to replace petroleum-based chemicals, promote the development of renewable energy, and have important significance for realizing low-carbon economic development. 5-hydroxymethylfurfural (5-HMF) is one of the important bio-based chemicals, and its derivative compounds can replace a variety of monomers used for synthesizing polymers. Among them, 2,5-furan dicarboxylic acid (FDCA) is the most valuable one because it is the main monomer for synthesizing polyethylene furandicarboxylate (PEF), which is widely considered as a viable alternative to polyethylene terephthalate (PET) in food and beverage packaging. At present, in the process of synthesizing FDCA from 5-HMF, noble metal doped carbon material catalysts are widely used, and the efficiency needs to be improved. The noble metals used are expensive and difficult to adapt to large-scale industrial production. Therefore, how to develop a new type of porous carbon-based catalyst to improve the efficiency of synthesizing bio-based FDCA is of great significance for the industrial application of converting biomass into high-value energy chemicals, and is also a difficult problem that the field has been eager to solve. SUMMARY

[0003] The application provides a bimetallic doped multi-level porous carbon catalyst and a preparation method and application thereof. The bimetallic doped multi-level porous carbon catalyst is prepared from two transition metal salts and a specific biomass powder as raw materials through a hydrothermal reaction and high-temperature calcination. The catalyst has low cost and simple preparation process, and can efficiently catalyze the synthesis of 2,5-furan dicarboxylic acid from 5-hydroxymethylfurfural under mild conditions, thereby solving the problems of unstable biological enzyme catalytic system and expensive noble metal catalytic system in the synthesis of 2,5-furan dicarboxylic acid in the prior art.

[0004] The application is implemented by the following technical solutions.

[0005] A preparation method of a bimetallic doped multi-level porous carbon catalyst, comprising the following steps:

[0006] The biomass powder is selected from any one of agarose, chitosan, glucose, xylose, ascorbic acid, the metal salt R1 is selected from any one of ferrous chloride, ferrous sulfate, manganese carbonate, manganese nitrate, nickel nitrate, the metal salt R2 is selected from any one of cobalt nitrate, cobalt sulfate, the mixture is transferred to a hydrothermal reactor, and reaction is carried out at 160-180 DEG C for 1-4h, centrifugal separation is carried out to obtain a solid, the solid is transferred to a crucible and placed in a muffle furnace to be heated to 200-500 DEG C at a rate of 5-20 DEG C / min for calcination for 1-4h, and a bimetallic doped hierarchical porous carbon catalyst is obtained after natural cooling.

[0007] Preferably, the mass ratio of the metal salt R1 and the metal salt R2 is (1-5):(1-5).

[0008] Preferably, the mass ratio of the biomass powder and the composite metal salt is (1-5):5.

[0009] The application also protects the bimetallic doped hierarchical porous carbon catalyst obtained by the above preparation method.

[0010] The application also protects the application of the bimetallic doped hierarchical porous carbon catalyst in the synthesis of 2,5-furan dicarboxylic acid, the bimetallic doped hierarchical porous carbon catalyst and 5-hydroxymethylfurfural are added into an alkaline aqueous solution, reaction is carried out at 110-150 DEG C under an air pressure of 1.5-3 MPa for 1-6h, after the reaction is completed, the solid catalyst is filtered, the solution pH is adjusted by using an acid, the product is centrifuged and freeze-dried to obtain 2,5-furan dicarboxylic acid solid.

[0011] Preferably, the reaction temperature is 120-130 DEG C.

[0012] Preferably, the reaction time is 2-4h.

[0013] Preferably, the air pressure is 2-2.5 MPa.

[0014] Preferably, the mass ratio of 5-hydroxymethylfurfural and the bimetallic doped hierarchical porous carbon catalyst is (1-3):(1-3).

[0015] Preferably, the alkaline aqueous solution is a sodium bicarbonate aqueous solution, and the mass-volume ratio of 5-hydroxymethylfurfural and the sodium bicarbonate aqueous solution is 1-8g / L.

[0016] The application has the following beneficial effects:

[0017] The bimetallic doped hierarchical porous carbon catalyst component in the application is simple, cheap and simple in preparation process. The catalyst can efficiently catalyze the synthesis of 2,5-furan dicarboxylic acid from 5-hydroxymethylfurfural under mild conditions. The obtained target product has high yield, is easy to separate and has good industrial application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the SEM morphology diagram of the bimetallic doped hierarchical porous carbon catalyst prepared in Example 1.

[0019] Figure 2 is the process flow diagram of the bimetallic doped hierarchical porous carbon catalyst catalyzing the synthesis of 2,5-furan dicarboxylic acid from 5-hydroxymethylfurfural. DETAILED DESCRIPTION

[0020] Those skilled in the art will understand that the technology disclosed in the following examples represents the technology discovered by the inventors to play a good role in the practice of the application. However, many changes can be made in the disclosed specific embodiments and still obtain the same or similar results without departing from the spirit and scope of the application.

[0021] Example 1

[0022] Preparation method of bimetallic doped hierarchical porous carbon catalyst: composite metal salt was prepared by grinding and blending 5g of manganese carbonate and 5g of cobalt nitrate in a mortar. 4g of xylose was added to the mortar and mixed, then the mixture was transferred to a hydrothermal reaction kettle and reacted at 170℃ for 2h. The solid was separated by centrifugation, transferred to a crucible and placed in a muffle furnace at 300℃ for calcination for 3h at a heating rate of 10℃ / min. After natural cooling, 3.6g of bimetallic doped hierarchical porous carbon catalyst was obtained.

[0023] Steps of bimetallic doped hierarchical porous carbon catalyst catalyzing the synthesis of 2,5-furan dicarboxylic acid:

[0024] 0.2g of bimetallic doped hierarchical porous carbon catalyst and 0.4g of 5-hydroxymethylfurfural were added to 100ml of 1g / L sodium bicarbonate aqueous solution. The reaction was carried out in a reaction kettle with air pressure of 2MPa and reaction temperature of 130℃ for 4h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, centrifuged and freeze-dried to obtain 0.491g of FDCA solid, with a yield of 99.3% of FDCA.

[0025] Comparative Example 1

[0026] Preparation of Cu / Mn bimetallic catalyst: 81 g of potassium permanganate, 64 g of copper nitrate trihydrate and 3.2 g of water were mixed, stirred at 1000 rpm and 200°C for 2 h, filtered, and the obtained solid phase was washed with ethanol and deionized water in sequence and dried at 100°C for 2 h to obtain an amorphous Cu / Mn bimetallic catalyst precursor; the prepared amorphous Cu / Mn bimetallic catalyst precursor was mixed with 5 g of activated alumina, dried at 100°C overnight, and then calcined at 250°C for 2 h under a nitrogen atmosphere to obtain a Cu / Mn bimetallic catalyst (detection showed that the loading of Cu was 13%, the loading of Mn was 16%, and the molar ratio of Cu to Mn was 1.0:1.5.

[0027] Synthesis of 2,5-furan dicarboxylic acid catalyzed by Cu / Mn bimetallic catalyst: 500 g of 5-hydroxymethylfurfural and 145 g of Cu / Mn bimetallic catalyst were added to a high-pressure reaction kettle to form a mixed reaction system, the gas in the reaction kettle was replaced with nitrogen three times, the pressure of nitrogen was maintained at 0.1 MPa, heating was performed at a temperature of 450°C, at the same time, a 2 mol / L sodium hydroxide aqueous solution was added to the reaction system to maintain the pH value of the system at 8, and nitrogen was continuously introduced to maintain the pressure in the kettle basically unchanged, heating was stopped after 4 h, filtration was performed, the pH value of the obtained filtrate was adjusted to 4 with a 5 mol / L hydrochloric acid, filtration was performed again, washing was performed with water, and drying was performed at 70°C to obtain 450 g of 2,5-furan dicarboxylic acid with a purity of 98.57%, a conversion rate of 5-hydroxymethylfurfural of 94.5%, and a yield of 2,5-furan dicarboxylic acid of 89.8%.

[0028] It can be known from the results of Example 1 and Comparative Example 1 that the Cu / Mn bimetallic catalytic system adopted in Comparative Example 1 has a lower effect than that in Example 1.

[0029] Comparative Example 2

[0030] Preparation method of platinum-cobalt-niobium heterogeneous catalyst: 0.001 mol of niobium oxalate hydrate was dissolved in 100 mL of deionized water to obtain a Nb precursor solution, and 0.01 mol of cobalt nitrate was dissolved in 100 mL of deionized water to obtain a Co precursor solution;

[0031] Preparation of Nb@Co carrier: the pH value of the Nb precursor solution was adjusted to 7 using a NaOH solution (1 mol L-1), the Co precursor solution was added under stirring at 600 rpm, the molar ratio of Nb to Co was 0.1, after stirring for 10 min, the pH value of the mixture was further adjusted to 9 using a NaOH solution, the obtained suspension was stirred at 600 rpm at ambient temperature for 2 h, the obtained solid was washed with excess deionized water until the pH value of the filtrate was neutral, and the obtained solid was calcined at 400°C for 4 h to obtain a Nb@Co composite oxide carrier;

[0032] A mixture of 0.01 mmol sodium hexahydrate hexachloroplatinate and 10 mg PVP was mixed in 200 mL deionized water, stirred at 600 rpm for 1 h, 390 mg Nb@Co support was added and stirred for another 1 h, 2.5 mL NaBH4 solution with a concentration of 4 mg / mL was added dropwise, the obtained suspension was continuously stirred for another 2 h, the solid was recovered by filtration, washed repeatedly with excess deionized water, the obtained solid was dried at 110 °C overnight, and the Nb@Co-Pt catalyst with a loading of 0.5 wt% was obtained.

[0033] Synthesis of 2,5-furandicarboxylic acid catalyzed by platinum-cobalt-niobium heterogeneous catalyst: 1 mmol 5-hydroxymethylfurfural, 20 mL deionized water, and catalyst (molar ratio of HMF to Pt in the catalyst was 100:1) were added into the polytetrafluoroethylene liner (50 mL) of a high-pressure reaction kettle with a magnetic stirrer, the reaction kettle was sealed and treated, purged with 5 bar oxygen three times, 10 bar oxygen was filled in the kettle, at this time the reaction kettle was tested for leakage to ensure that it was airtight; the reaction kettle was placed in a constant temperature oil bath at 100 °C, the stirring rate was 2000 rpm, and the oxidation reaction was carried out for 6 h to obtain a reaction product liquid. The HMF conversion rate was 100%, and the selectivity of 2,5-furandicarboxylic acid was >99%.

[0034] The catalyst preparation process of Comparative Example 2 is complex, and the price of platinum noble metal is high, resulting in high cost of FDCA synthesis.

[0035] Comparative Example 3

[0036] Reference Example 1, except that no biomass xylose was added, and the other steps were the same as in Example 1.

[0037] Preparation method of bimetallic doped hierarchical porous carbon catalyst: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, and then the mixture was transferred to a hydrothermal reaction kettle and reacted at 170 °C for 2 h. The solid was separated by centrifugation, transferred to a crucible and calcined in a muffle furnace at 300 °C for 3 h at a heating rate of 10 °C / min, and then naturally cooled to obtain 2.6 g of a bimetallic doped hierarchical porous carbon catalyst.

[0038] Steps for synthesizing 2,5-furandicarboxylic acid catalyzed by bimetallic doped hierarchical porous carbon catalyst:

[0039] 0.2 g of bimetallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added to 100 mL of a sodium bicarbonate aqueous solution with a concentration of 1 g / L, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130 °C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and the solid FDCA was obtained by centrifugal separation and freeze-drying. The yield of FDCA was 75.4%.

[0040] Comparative Example 4

[0041] Reference Example 1, except that no biomass xylose was added, and a commercial activated carbon was mixed with a composite metal salt to prepare a double metal doped activated carbon-based catalyst, and the other steps were the same as Example 1.

[0042] The preparation method of the double metal doped multi-level porous carbon catalyst: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of a commercial activated carbon was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid was obtained by centrifugal separation, transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a heating rate of 10°C / min, and the double metal doped multi-level porous carbon catalyst 6.3 g was obtained after natural cooling.

[0043] The steps of the double metal doped multi-level porous carbon catalyst for catalytic synthesis of 2,5-furan dicarboxylic acid:

[0044] 0.2 g of the double metal doped multi-level porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added to 100 ml of a 1 g / L sodium bicarbonate aqueous solution, and the reaction was carried out in a reaction kettle under an air pressure of 2 MPa and at a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, centrifugal separation and freeze-drying were carried out to obtain 0.402 g of FDCA solid, and the FDCA yield was 81.2%.

[0045] From the experimental results of Examples 1 and Comparative Examples 3-4, it can be seen that the porous carbon-based prepared from biomass xylose as a carrier of a double metal catalytic system has a higher FDCA yield for catalytic synthesis of 2,5-furan dicarboxylic acid.

[0046] Example 2

[0047] The preparation method of the double metal doped multi-level porous carbon catalyst: 5 g of manganese carbonate and 15 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 12 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid was obtained by centrifugal separation, transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a heating rate of 10°C / min, and the double metal doped multi-level porous carbon catalyst 8.2 g was obtained after natural cooling.

[0048] The steps of the double metal doped multi-level porous carbon catalyst for catalytic synthesis of 2,5-furan dicarboxylic acid:

[0049] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were carried out to obtain 0.473 g of FDCA solid, with an FDCA yield of 95.6%.

[0050] Example 3

[0051] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 25 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 6 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 2 h at a temperature increase rate of 20°C / min, and after natural cooling, 9.1 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0052] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0053] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were carried out to obtain 0.473 g of FDCA solid, with an FDCA yield of 95.6%.

[0054] Example 4

[0055] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 15 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 12 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 180°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 200°C for 4 h at a temperature increase rate of 10°C / min, and after natural cooling, 8.4 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0056] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0057] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the bimetallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were carried out to obtain 0.451 g of FDCA solid, with a yield of FDCA of 91.2%.

[0058] Example 5

[0059] The preparation method of the bimetallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 160°C for 3 h. The solid was obtained by centrifugal separation, transferred to a crucible, and calcined in a muffle furnace at 400°C for 2 h at a heating rate of 10°C / min. After natural cooling, 3.4 g of the bimetallic doped hierarchical porous carbon catalyst was obtained.

[0060] The steps of the bimetallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0061] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 mg / mL, 0.3 g of the bimetallic doped hierarchical porous carbon catalyst and 0.6 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2.5 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were carried out to obtain 0.692 g of FDCA solid, with a yield of FDCA of 93.1%.

[0062] Example 6

[0063] The preparation method of the bimetallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 6 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid was obtained by centrifugal separation, transferred to a crucible, and calcined in a muffle furnace at 500°C for 2 h at a heating rate of 20°C / min. After natural cooling, 4.3 g of the bimetallic doped hierarchical porous carbon catalyst was obtained.

[0064] The steps of the bimetallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0065] To 100 ml of a sodium bicarbonate aqueous solution with a concentration of 0.75 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.6 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 3 MPa and a reaction temperature of 140°C for 3 h. After the reaction was completed, the catalyst was filtered, the solution was adjusted to a pH of 3 with acid, and centrifugal separation and freeze-drying were performed to obtain 0.708 g of FDCA solid, with a yield of FDCA of 95.4%.

[0066] Example 7

[0067] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 15 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 8 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and calcined in a muffle furnace at 300°C for 4 h at a temperature increase rate of 10°C / min, and after natural cooling, 7.2 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0068] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0069] To 100 ml of a sodium bicarbonate aqueous solution with a concentration of 1 g / L, 1.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 120°C for 2 h. After the reaction was completed, the catalyst was filtered, the solution was adjusted to a pH of 3 with acid, and centrifugal separation and freeze-drying were performed to obtain 0.443 g of FDCA solid, with a yield of FDCA of 89.5%.

[0070] Example 8

[0071] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 15 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 8 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 180°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and calcined in a muffle furnace at 300°C for 4 h at a temperature increase rate of 10°C / min, and after natural cooling, 6.9 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0072] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0073] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 2 g / L, 1.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2.5 MPa and a reaction temperature of 120°C for 6 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were performed to obtain 0.408 g of FDCA solid, with a yield of FDCA of 82.5%.

[0074] Example 9

[0075] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 25 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 12 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 4 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 200°C for 4 h at a temperature increase rate of 20°C / min, and the double-metallic doped hierarchical porous carbon catalyst 12.4 g was obtained after natural cooling.

[0076] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0077] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1.3 g / L, 0.8 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2.5 MPa and a reaction temperature of 130°C for 5 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were performed to obtain 0.462 g of FDCA solid, with a yield of FDCA of 93.4%.

[0078] Example 10

[0079] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min, and the double-metallic doped hierarchical porous carbon catalyst 3.6 g was obtained after natural cooling.

[0080] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0081] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.4 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were carried out to obtain 0.451 g of FDCA solid, with a yield of FDCA of 91.2%.

[0082] Example 11

[0083] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of agarose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and calcined in a muffle furnace at 300°C for 3 h at a heating rate of 10°C / min, and after natural cooling, 3.9 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0084] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0085] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 with acid, and centrifugal separation and freeze-drying were carried out to obtain 0.466 g of FDCA solid, with a yield of FDCA of 94.2%.

[0086] Example 12

[0087] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of chitosan was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and calcined in a muffle furnace at 300°C for 3 h at a heating rate of 10°C / min, and after natural cooling, 3.8 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0088] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0089] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were performed to obtain 0.458 g of FDCA solid, with a yield of FDCA of 92.5%.

[0090] Example 13

[0091] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of glucose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min. After natural cooling, 3.7 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0092] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0093] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were performed to obtain 0.458 g of FDCA solid, with a yield of FDCA of 92.5%.

[0094] Example 14

[0095] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt nitrate were ground and blended in a mortar to prepare a composite metal salt, 4 g of ascorbic acid was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min. After natural cooling, 3.3 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0096] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0097] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were performed to obtain 0.487 g of FDCA solid, with a yield of FDCA of 98.5%.

[0098] Example 15

[0099] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt sulfate were ground and blended in a mortar to prepare a composite metal salt, 4 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min. After natural cooling, 3.1 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0100] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0101] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were performed to obtain 0.487 g of FDCA solid, with a yield of FDCA of 98.5%.

[0102] Example 16

[0103] The preparation method of the double-metallic doped hierarchical porous carbon catalyst was as follows: 5 g of manganese carbonate and 5 g of cobalt sulfate were ground and blended in a mortar to prepare a composite metal salt, 4 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. The solid obtained by centrifugal separation was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min. After natural cooling, 3.1 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0104] The steps of the double-metallic doped hierarchical porous carbon catalyst for catalyzing the synthesis of 2,5-furan dicarboxylic acid were as follows:

[0105] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were carried out to obtain 0.406 g of FDCA solid, with a yield of FDCA of 82.1%.

[0106] Example 17

[0107] Method for preparing the double-metallic doped hierarchical porous carbon catalyst: 5 g of nickel nitrate and 5 g of cobalt sulfate were ground and blended in a mortar to prepare a composite metal salt, 4 g of xylose was added to the mortar for mixing, and then the mixture was transferred to a hydrothermal reaction kettle for reaction at 170°C for 2 h. Centrifugal separation was carried out to obtain a solid, which was transferred to a crucible and placed in a muffle furnace for calcination at 300°C for 3 h at a temperature increase rate of 10°C / min, and after natural cooling, 3.8 g of the double-metallic doped hierarchical porous carbon catalyst was obtained.

[0108] Step for synthesizing 2,5-furan dicarboxylic acid catalyzed by the double-metallic doped hierarchical porous carbon catalyst:

[0109] To 100 ml of sodium bicarbonate aqueous solution with a concentration of 1 g / L, 0.2 g of the double-metallic doped hierarchical porous carbon catalyst and 0.4 g of 5-hydroxymethylfurfural were added, and the reaction was carried out in a reaction kettle with an air pressure of 2 MPa and a reaction temperature of 130°C for 4 h. After the reaction was completed, the catalyst was filtered, the solution pH was adjusted to 3 using acid, and centrifugal separation and freeze-drying were carried out to obtain 0.406 g of FDCA solid, with a yield of FDCA of 82.1%.

[0110] Although the present application has been described with reference to the illustrative embodiments, it will be understood by those skilled in the art that various other changes in form and details can be made therein without departing from the spirit and scope of the application. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from its scope. Therefore, it is intended that the present application not be limited to the particular disclosed embodiments described but will include all embodiments falling within the scope of the appended claims.

Claims

1. Use of a bimetallic doped hierarchical porous carbon catalyst in the synthesis of 2,5-furan dicarboxylic acid, characterized in that, The bimetallic doped hierarchical porous carbon catalyst and 5-hydroxymethylfurfural are added into an alkaline aqueous solution, the mass ratio of 5-hydroxymethylfurfural to the bimetallic doped hierarchical porous carbon catalyst is (1-3):(1-3), under the air pressure of 1.5-3 MPa, the reaction is carried out at 110-150℃ for 1-6 h, after the reaction is completed, the solid catalyst is filtered, the solution pH is adjusted by using an acid, the product is centrifuged and freeze-dried to obtain 2,5-furan dicarboxylic acid solid; The preparation method of the bimetallic doped hierarchical porous carbon catalyst comprises the following steps: biomass powder and a composite metal salt component composed of metal salt R1 and R2 are ground and blended in a mortar, the biomass powder is selected from any one of agarose, chitosan, glucose, xylose and ascorbic acid, the metal salt R1 is selected from any one of ferrous chloride, ferrous sulfate, manganese carbonate, manganese nitrate and nickel nitrate, the metal salt R2 is selected from any one of cobalt nitrate and cobalt sulfate, the mass ratio of the biomass powder to the composite metal salt is (1-5):5, then the mixture is transferred to a hydrothermal reaction kettle, and the reaction is carried out at 160-180℃ for 1-4 h, the solid is obtained by centrifugal separation, the solid is transferred to a crucible and placed in a muffle furnace, and the temperature is increased to 200-500℃ at a rate of 5-20℃ / min for calcination for 1-4 h, and the bimetallic doped hierarchical porous carbon catalyst is obtained after natural cooling.

2. Use according to claim 1, characterized in that, The mass ratio of the metal salt R1 to the metal salt R2 is (1-5):(1-5).

3. Use according to claim 1, characterized in that, The reaction temperature in the process of synthesizing 2,5-furan dicarboxylic acid is 120-130℃.

4. Use according to claim 1, characterized in that, The reaction time in the process of synthesizing 2,5-furan dicarboxylic acid is 2-4 h.

5. The use according to claim 1, characterized in that, The air pressure in the process of synthesizing 2,5-furan dicarboxylic acid is 2-2.5 MPa.

6. Use according to claim 1, characterized in that, The alkaline aqueous solution is a sodium bicarbonate aqueous solution, and the mass-volume ratio of 5-hydroxymethylfurfural to the sodium bicarbonate aqueous solution is 1-8 g / L.

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